Construction of edge cracks pre-criterion model based on hot rolling experiment and simulation of AZ31 magnesium alloy

Various fracture criteria, especially Johnson and Cook (J-C) model and (normalized) Cockcroft and Latham (C-L) criterion were contrasted and discussed. Based on normalized C-L criterion, adopted in this paper, FE simulation was carried out and hot rolling experiments under temperature range of 200 degrees C-350 degrees C,rolling reduction rate of 25%-40% and rolling speed from 7-21 r/min was implemented. The microstructure was observed by optical microscope and damage values of simulation results were contrasted with the length of cracks on diverse parameters. The results show that the plate generated less edge cracks and the microstructure emerged slight shear bands and fine dynamic recrystallization grains rolled at 350 degrees C, 40% reduction and 14 r/min. The edge cracks precriterion model was obtained combined with Zener-Hollomon equation and deformation activation energy.